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MySQL > mysql server status variables > Flashcards

mysql server status variables Flashcards

1
Q

Aborted_clients

A

The number of connections that were aborted because the client died without closing the connection properly. SeeSectionC.5.2.11 “Communication Errors and Aborted Connections”.

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2
Q

Aborted_connects

A

The number of failed attempts to connect to the MySQL server. SeeSectionC.5.2.11 “Communication Errors and Aborted Connections”.
For additional connection-related information check theConnection_errors_xxxstatus variables and thehost_cachetable.

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3
Q

Binlog_cache_disk_use

A

The number of transactions that used the temporary binary log cache but that exceeded the value ofbinlog_cache_sizeand used a temporary file to store statements from the transaction.
The number of nontransactional statements that caused the binary log transaction cache to be written to disk is tracked separately in theBinlog_stmt_cache_disk_usestatus variable.

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4
Q

Binlog_cache_use

A

The number of transactions that used the binary log cache.

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5
Q

Binlog_stmt_cache_disk_use

A

The number of nontransaction statements that used the binary log statement cache but that exceeded the value ofbinlog_stmt_cache_sizeand used a temporary file to store those statements.

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6
Q

Binlog_stmt_cache_use

A

The number of nontransactional statements that used the binary log statement cache.

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7
Q

Bytes_received

A

The number of bytes received from all clients.

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8
Q

Bytes_sent

A

The number of bytes sent to all clients.

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9
Q

Com_xxx

A

The Com_xxx statement counter variables indicate the number of times each xxx statement has been executed. There is one status variable for each type of statement. For example Com_delete and Com_update count DELETE and UPDATE statements respectively. Com_delete_multi and Com_update_multi are similar but apply to DELETE and UPDATE statements that use multiple-table syntax.

If a query result is returned from query cache the server increments the Qcache_hits status variable not Com_select. See Section 8.9.3.4 “Query Cache Status and Maintenance”.

All of the Com_stmt_xxx variables are increased even if a prepared statement argument is unknown or an error occurred during execution. In other words their values correspond to the number of requests issued not to the number of requests successfully completed.

The Com_stmt_xxx status variables are as follows:

Com_stmt_prepare

Com_stmt_execute

Com_stmt_fetch

Com_stmt_send_long_data

Com_stmt_reset

Com_stmt_close

Those variables stand for prepared statement commands. Their names refer to the COM_xxx command set used in the network layer. In other words their values increase whenever prepared statement API calls such as mysql_stmt_prepare() mysql_stmt_execute() and so forth are executed. However Com_stmt_prepare Com_stmt_execute and Com_stmt_close also increase for PREPARE EXECUTE or DEALLOCATE PREPARE respectively. Additionally the values of the older statement counter variables Com_prepare_sql Com_execute_sql and Com_dealloc_sql increase for the PREPARE EXECUTE and DEALLOCATE PREPARE statements. Com_stmt_fetch stands for the total number of network round-trips issued when fetching from cursors.

Com_stmt_reprepare indicates the number of times statements were automatically reprepared by the server after metadata changes to tables or views referred to by the statement. A reprepare operation increments Com_stmt_reprepare and also Com_stmt_prepare.

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10
Q

Compression

A

Whether the client connection uses compression in the client/server protocol.

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11
Q

Connection_errors_accept

A

The number of errors that occurred during calls toaccept()on the listening port.

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12
Q

Connection_errors_internal

A

The number of connections refused due to internal errors in the server such as failure to start a new thread or an out-of-memory condition.

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13
Q

Connection_errors_max_connections

A

The number of connections refused because the servermax_connectionslimit was reached.

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14
Q

Connection_errors_peer_addr

A

The number of errors that occurred while searching for connecting client IP addresses.

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15
Q

Connection_errors_select

A

The number of errors that occurred during calls toselect()orpoll()on the listening port. (Failure of this operation does not necessarily means a client connection was rejected.)

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16
Q

Connection_errors_tcpwrap

A

The number of connections refused by thelibwraplibrary.

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17
Q

Connection_errors_xxx

A

These variables provide information about errors that occur during the client connection process. They are global only and represent error counts aggregated across connections from all hosts. These variables track errors not accounted for by the host cache (seeSection8.11.5.2 “DNS Lookup Optimization and the Host Cache”) such as errors that are not associated with TCP connections occur very early in the connection process (even before an IP address is known) or are not specific to any particular IP address (such as out-of-memory conditions). These variables were added in MySQL 5.6.5.

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18
Q

Connections

A

The number of connection attempts (successful or not) to the MySQL server.

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19
Q

Created_tmp_disk_tables

A

The number of internal on-disk temporary tables created by the server while executing statements.

If an internal temporary table is created initially as an in-memory table but becomes too large MySQL automatically converts it to an on-disk table. The maximum size for in-memory temporary tables is the minimum of the tmp_table_size and max_heap_table_size values. If Created_tmp_disk_tables is large you may want to increase the tmp_table_size or max_heap_table_size value to lessen the likelihood that internal temporary tables in memory will be converted to on-disk tables.

You can compare the number of internal on-disk temporary tables created to the total number of internal temporary tables created by comparing the values of the Created_tmp_disk_tables and Created_tmp_tables variables.

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20
Q

Created_tmp_files

A

How many temporary filesmysqldhas created.

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21
Q

Created_tmp_tables

A

The number of internal temporary tables created by the server while executing statements.

You can compare the number of internal on-disk temporary tables created to the total number of internal temporary tables created by comparing the values of the Created_tmp_disk_tables and Created_tmp_tables variables.

See also Section 8.4.4 “How MySQL Uses Internal Temporary Tables”.

Each invocation of the SHOW STATUS statement uses an internal temporary table and increments the global Created_tmp_tables value.

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22
Q

Delayed_errors

A

deprecated as of 5.6.7

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23
Q

Delayed_insert_threads

A

deprecated as of 5.6.7

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24
Q

Delayed_writes

A

deprecated as of 5.6.7

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25
Q

Flush_commands

A

The number of times the server flushes tables whether because a user executed aFLUSH TABLESstatement or due to internal server operation. It is also incremented by receipt of aCOM_REFRESHpacket. This is in contrast toCom_flush which indicates how manyFLUSHstatements have been executed whetherFLUSH TABLESFLUSH LOGS and so forth.

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26
Q

Handler_commit

A

The number of internalCOMMITstatements.

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27
Q

Handler_delete

A

The number of times that rows have been deleted from tables.

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28
Q

Handler_external_lock

A

The server increments this variable for each call to itsexternal_lock()function which generally occurs at the beginning and end of access to a table instance. There might be differences among storage engines. This variable can be used for example to discover for a statement that accesses a partitioned table how many partitions were pruned before locking occurred: Check how much the counter increased for the statement subtract 2 (2 calls for the table itself) then divide by 2 to get the number of partitions locked. This variable was added in MySQL 5.6.2.

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29
Q

Handler_mrr_init

A

The number of times the server uses a storage engines own Multi-Range Read implementation for table access. This variable was added in MySQL 5.6.1.

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30
Q

Handler_prepare

A

A counter for the prepare phase of two-phase commit operations.

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31
Q

Handler_read_first

A

The number of times the first entry in an index was read. If this value is high it suggests that the server is doing a lot of full index scans; for exampleSELECT col1 FROM foo assuming thatcol1is indexed.

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32
Q

Handler_read_key

A

The number of requests to read a row based on a key. If this value is high it is a good indication that your tables are properly indexed for your queries.

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33
Q

Handler_read_last

A

The number of requests to read the last key in an index. WithORDER BY the server will issue a first-key request followed by several next-key requests whereas with WithORDER BY DESC the server will issue a last-key request followed by several previous-key requests. This variable was added in MySQL 5.6.1.

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34
Q

Handler_read_next

A

The number of requests to read the next row in key order. This value is incremented if you are querying an index column with a range constraint or if you are doing an index scan.

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35
Q

Handler_read_prev

A

The number of requests to read the previous row in key order. This read method is mainly used to optimizeORDER BY … DESC.

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36
Q

Handler_read_rnd

A

The number of requests to read a row based on a fixed position. This value is high if you are doing a lot of queries that require sorting of the result. You probably have a lot of queries that require MySQL to scan entire tables or you have joins that do not use keys properly.

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37
Q

Handler_read_rnd_next

A

The number of requests to read the next row in the data file. This value is high if you are doing a lot of table scans. Generally this suggests that your tables are not properly indexed or that your queries are not written to take advantage of the indexes you have.

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38
Q

Handler_rollback

A

The number of requests for a storage engine to perform a rollback operation.

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39
Q

Handler_savepoint

A

The number of requests for a storage engine to place a savepoint.

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40
Q

Handler_savepoint_rollback

A

The number of requests for a storage engine to roll back to a savepoint.

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41
Q

Handler_update

A

The number of requests to update a row in a table.

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42
Q

Handler_write

A

The number of requests to insert a row in a table.

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43
Q

Innodb_available_undo_logs

A

The total number of availableInnoDBundo logs. Supplements theinnodb_undo_logssystem variable which reports the number of active undo logs.

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44
Q

Innodb_buffer_pool_bytes_data

A

The total number of bytes in theInnoDBbuffer poolcontaining data. The number includes bothdirtyand clean pages. For more accurate memory usage calculations than withInnodb_buffer_pool_pages_data whencompressedtables cause the buffer pool to hold pages of different sizes.

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45
Q

Innodb_buffer_pool_bytes_dirty

A

The total current number of bytes held indirty pagesin theInnoDBbuffer pool. For more accurate memory usage calculations than withInnodb_buffer_pool_pages_dirty whencompressedtables cause the buffer pool to hold pages of different sizes.

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46
Q

Innodb_buffer_pool_dump_status

A

The progress of an operation to record thepagesheld in theInnoDBbuffer pool triggered by the setting ofinnodb_buffer_pool_dump_at_shutdownorinnodb_buffer_pool_dump_now.

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47
Q

Innodb_buffer_pool_load_status

A

The progress of an operation towarm uptheInnoDBbuffer poolby reading in a set ofpagescorresponding to an earlier point in time triggered by the setting ofinnodb_buffer_pool_load_at_startuporinnodb_buffer_pool_load_now. If the operation introduces too much overhead you can cancel it by settinginnodb_buffer_pool_load_abort.

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48
Q

Innodb_buffer_pool_pages_data

A

The number ofpagesin theInnoDBbuffer poolcontaining data. The number includes bothdirtyand clean pages.

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49
Q

Innodb_buffer_pool_pages_dirty

A

The current number ofdirty pagesin theInnoDBbuffer pool.

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50
Q

Innodb_buffer_pool_pages_flushed

A

The number of requests toflushpagesfrom theInnoDBbuffer pool.

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51
Q

Innodb_buffer_pool_pages_free

A

The number of freepagesin theInnoDBbuffer pool.

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52
Q

Innodb_buffer_pool_pages_latched

A

The number of latchedpagesin theInnoDBbuffer pool. These are pages currently being read or written or that cannot beflushedor removed for some other reason. Calculation of this variable is expensive so it is available only when theUNIV_DEBUGsystem is defined at server build time.

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53
Q

Innodb_buffer_pool_pages_misc

A

The number ofpagesin theInnoDBbuffer poolthat are busy because they have been allocated for administrative overhead such asrow locksor theadaptive hash index. This value can also be calculated asInnodb_buffer_pool_pages_total–Innodb_buffer_pool_pages_free–Innodb_buffer_pool_pages_data.

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54
Q

Innodb_buffer_pool_pages_total

A

The total size of theInnoDBbuffer pool inpages.

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55
Q

Innodb_buffer_pool_read_ahead

A

The number ofpagesread into theInnoDBbuffer poolby theread-aheadbackground thread.

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56
Q

Innodb_buffer_pool_read_ahead_evicted

A

The number ofpagesread into theInnoDBbuffer poolby theread-aheadbackground thread that were subsequentlyevictedwithout having been accessed by queries.

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57
Q

Innodb_buffer_pool_read_requests

A

The number of logical read requests made to theInnoDBbuffer pool. These requests could be serviced by returning data that was already in memory or by reading the data from disk into memory first.

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58
Q

Innodb_buffer_pool_reads

A

The number of logical reads thatInnoDBcould not satisfy from thebuffer pool and had to read directly from disk.

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59
Q

Innodb_buffer_pool_wait_free

A

Normally writes to theInnoDBbuffer poolhappen in the background. WhenInnoDBneeds to read or create apageand no clean pages are availableInnoDBflushes somedirty pagesfirst and waits for that operation to finish. This counter counts instances of these waits. Ifinnodb_buffer_pool_sizehas been set properly this value should be small.

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60
Q

Innodb_buffer_pool_write_requests

A

The number of writes done to theInnoDBbuffer pool.

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61
Q

Innodb_data_fsyncs

A

The number offsync()operations so far. The frequency offsync()calls is influenced by the setting of theinnodb_flush_methodconfiguration option.

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62
Q

Innodb_data_pending_fsyncs

A

The current number of pendingfsync()operations. The frequency offsync()calls is influenced by the setting of theinnodb_flush_methodconfiguration option.

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63
Q

Innodb_data_pending_reads

A

The current number of pending reads.

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64
Q

Innodb_data_pending_writes

A

The current number of pending writes.

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65
Q

Innodb_data_read

A

The amount of data read since the server was started.

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66
Q

Innodb_data_reads

A

The total number of data reads.

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67
Q

Innodb_data_writes

A

The total number of data writes.

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68
Q

Innodb_data_written

A

The amount of data written so far in bytes.

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69
Q

Innodb_dblwr_pages_written

A

The number ofpagesthat have been written to thedoublewrite buffer. SeeSection14.2.10.1 “InnoDBDisk I/O”.

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70
Q

Innodb_dblwr_writes

A

The number of doublewrite operations that have been performed. SeeSection14.2.10.1 “InnoDBDisk I/O”.

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71
Q

Innodb_have_atomic_builtins

A

Indicates whether the server was built withatomic instructions.

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72
Q

Innodb_log_waits

A

The number of times that thelog bufferwas too small and awaitwas required for it to beflushedbefore continuing.

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73
Q

Innodb_log_write_requests

A

The number of write requests for theInnoDBredo log.

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74
Q

Innodb_log_writes

A

The number of physical writes to theInnoDBredo logfile.

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75
Q

Innodb_num_open_files

A

The number of filesInnoDBcurrently holds open.

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76
Q

Innodb_os_log_fsyncs

A

The number offsync()writes done to theInnoDBredo logfiles.

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77
Q

Innodb_os_log_pending_fsyncs

A

The number of pendingfsync()operations for theInnoDBredo logfiles.

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78
Q

Innodb_os_log_pending_writes

A

The number of pending writes to theInnoDBredo logfiles.

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79
Q

Innodb_os_log_written

A

The number of bytes written to theInnoDBredo logfiles.

80
Q

Innodb_page_size

A

The compiled-inInnoDBpage size (default 16KB). Many values are counted in pages; the page size enables them to be easily converted to bytes.

81
Q

Innodb_pages_created

A

The number of pages created by operations onInnoDBtables.

82
Q

Innodb_pages_read

A

The number of pages read by operations onInnoDBtables.

83
Q

Innodb_pages_written

A

The number of pages written by operations onInnoDBtables.

84
Q

Innodb_row_lock_current_waits

A

The number ofrow lockscurrently being waited for by operations onInnoDBtables.

85
Q

Innodb_row_lock_time

A

The total time spent in acquiringrow locksforInnoDBtables in milliseconds.

86
Q

Innodb_row_lock_time_avg

A

The average time to acquire arow lockforInnoDBtables in milliseconds.

87
Q

Innodb_row_lock_time_max

A

The maximum time to acquire arow lockforInnoDBtables in milliseconds.

88
Q

Innodb_row_lock_waits

A

The number of times operations onInnoDBtables had to wait for arow lock.

89
Q

Innodb_rows_deleted

A

The number of rows deleted fromInnoDBtables.

90
Q

Innodb_rows_inserted

A

The number of rows inserted intoInnoDBtables.

91
Q

Innodb_rows_read

A

The number of rows read fromInnoDBtables.

92
Q

Innodb_rows_updated

A

The number of rows updated inInnoDBtables.

93
Q

Innodb_truncated_status_writes

A

The number of times output from theSHOW ENGINE INNODB STATUSstatement has been truncated.

94
Q

Key_blocks_not_flushed

A

The number of key blocks in theMyISAMkey cache that have changed but have not yet been flushed to disk.

95
Q

Key_blocks_unused

A

The number of unused blocks in theMyISAMkey cache. You can use this value to determine how much of the key cache is in use; see the discussion ofkey_buffer_sizeinSection5.1.4 “Server System Variables”.

96
Q

Key_blocks_used

A

The number of used blocks in theMyISAMkey cache. This value is a high-water mark that indicates the maximum number of blocks that have ever been in use at one time.

97
Q

Key_read_requests

A

The number of requests to read a key block from theMyISAMkey cache.

98
Q

Key_reads

A

The number of physical reads of a key block from disk into theMyISAMkey cache. IfKey_readsis large then yourkey_buffer_sizevalue is probably too small. The cache miss rate can be calculated asKey_reads/Key_read_requests.

99
Q

Key_write_requests

A

The number of requests to write a key block to theMyISAMkey cache.

100
Q

Key_writes

A

The number of physical writes of a key block from theMyISAMkey cache to disk.

101
Q

Last_query_cost

A

The total cost of the last compiled query as computed by the query optimizer. This is useful for comparing the cost of different query plans for the same query. The default value of 0 means that no query has been compiled yet. The default value is 0. Last_query_cost has session scope.

The Last_query_cost value can be computed accurately only for simple “flat” queries not complex queries such as those with subqueries or UNION. For the latter the value is set to 0.

102
Q

Last_query_partial_plans

A

The number of iterations the query optimizer made in execution plan construction for the previous query.Last_query_costhas session scope. This variable was added in MySQL 5.6.5.

103
Q

Max_used_connections

A

The maximum number of connections that have been in use simultaneously since the server started.

104
Q

Not_flushed_delayed_rows

A

deprecated as of 5.6.7

105
Q

Open_files

A

The number of files that are open. This count includes regular files opened by the server. It does not include other types of files such as sockets or pipes. Also the count does not include files that storage engines open using their own internal functions rather than asking the server level to do so.

106
Q

Open_streams

A

The number of streams that are open (used mainly for logging).

107
Q

Open_table_definitions

A

The number of cached.frmfiles.

108
Q

Open_tables

A

The number of tables that are open.

109
Q

Opened_files

A

The number of files that have been opened withmy_open()(amysyslibrary function). Parts of the server that open files without using this function do not increment the count.

110
Q

Opened_table_definitions

A

The number of.frmfiles that have been cached.

111
Q

Opened_tables

A

The number of tables that have been opened. IfOpened_tablesis big yourtable_open_cachevalue is probably too small.

112
Q

Prepared_stmt_count

A

The current number of prepared statements. (The maximum number of statements is given by themax_prepared_stmt_countsystem variable.)

113
Q

Qcache_free_blocks

A

The number of free memory blocks in the query cache.

114
Q

Qcache_free_memory

A

The amount of free memory for the query cache.

115
Q

Qcache_hits

A

The number of query cache hits.

116
Q

Qcache_inserts

A

The number of queries added to the query cache.

117
Q

Qcache_lowmem_prunes

A

The number of queries that were deleted from the query cache because of low memory.

118
Q

Qcache_not_cached

A

The number of noncached queries (not cacheable or not cached due to thequery_cache_typesetting).

119
Q

Qcache_queries_in_cache

A

The number of queries registered in the query cache.

120
Q

Qcache_total_blocks

A

The total number of blocks in the query cache.

121
Q

Queries

A

The number of statements executed by the server. This variable includes statements executed within stored programs unlike theQuestionsvariable. It does not countCOM_PINGorCOM_STATISTICScommands.

122
Q

Questions

A

The number of statements executed by the server. This includes only statements sent to the server by clients and not statements executed within stored programs unlike theQueriesvariable. This variable does not countCOM_PINGCOM_STATISTICSCOM_STMT_PREPARECOM_STMT_CLOSE orCOM_STMT_RESETcommands.

123
Q

Rpl_semi_sync_master_clients

A

The number of semisynchronous slaves.

This variable is available only if the master-side semisynchronous replication plugin is installed.

124
Q

Rpl_semi_sync_master_net_avg_wait_time

A

The average time in microseconds the master waited for a slave reply.

This variable is available only if the master-side semisynchronous replication plugin is installed.

125
Q

Rpl_semi_sync_master_net_wait_time

A

The total time in microseconds the master waited for slave replies.

This variable is available only if the master-side semisynchronous replication plugin is installed.

126
Q

Rpl_semi_sync_master_net_waits

A

The total number of times the master waited for slave replies.

This variable is available only if the master-side semisynchronous replication plugin is installed.

127
Q

Rpl_semi_sync_master_no_times

A

The number of times the master turned off semisynchronous replication.

This variable is available only if the master-side semisynchronous replication plugin is installed.

128
Q

Rpl_semi_sync_master_no_tx

A

The number of commits that were not acknowledged successfully by a slave.

This variable is available only if the master-side semisynchronous replication plugin is installed.

129
Q

Rpl_semi_sync_master_status

A

Whether semisynchronous replication currently is operational on the master. The value is ON if the plugin has been enabled and a commit acknowledgment has occurred. It is OFF if the plugin is not enabled or the master has fallen back to asynchronous replication due to commit acknowledgment timeout.

This variable is available only if the master-side semisynchronous replication plugin is installed.

130
Q

Rpl_semi_sync_master_timefunc_failures

A

The number of times the master failed when calling time functions such as gettimeofday().

This variable is available only if the master-side semisynchronous replication plugin is installed.

131
Q

Rpl_semi_sync_master_tx_avg_wait_time

A

The average time in microseconds the master waited for each transaction.

This variable is available only if the master-side semisynchronous replication plugin is installed.

132
Q

Rpl_semi_sync_master_tx_wait_time

A

The total time in microseconds the master waited for transactions.

This variable is available only if the master-side semisynchronous replication plugin is installed.

133
Q

Rpl_semi_sync_master_tx_waits

A

The total number of times the master waited for transactions.

This variable is available only if the master-side semisynchronous replication plugin is installed.

134
Q

Rpl_semi_sync_master_wait_pos_backtraverse

A

The total number of times the master waited for an event with binary coordinates lower than events waited for previously. This can occur when the order in which transactions start waiting for a reply is different from the order in which their binary log events are written.

This variable is available only if the master-side semisynchronous replication plugin is installed.

135
Q

Rpl_semi_sync_master_wait_sessions

A

The number of sessions currently waiting for slave replies.

This variable is available only if the master-side semisynchronous replication plugin is installed.

136
Q

Rpl_semi_sync_master_yes_tx

A

The number of commits that were acknowledged successfully by a slave.

This variable is available only if the master-side semisynchronous replication plugin is installed.

137
Q

Rpl_semi_sync_slave_status

A

Whether semisynchronous replication currently is operational on the slave. This is ON if the plugin has been enabled and the slave I/O thread is running OFF otherwise.

This variable is available only if the slave-side semisynchronous replication plugin is installed.

138
Q

Rsa_public_key

A

The RSA public key value used by the sha256_password authentication plugin. The value is nonempty only if the server successfully initializes the private and public keys in the files named by the sha256_password_private_key_path and sha256_password_public_key_path system variables. The value of Rsa_public_key comes from the latter file.

For information about sha256_password see Section 6.3.8.4 “The SHA-256 Authentication Plugin”.

This variable is available only if MySQL was built using OpenSSL. It was added in MySQL 5.6.6.

139
Q

Select_full_join

A

The number of joins that perform table scans because they do not use indexes. If this value is not 0 you should carefully check the indexes of your tables.

140
Q

Select_full_range_join

A

The number of joins that used a range search on a reference table.

141
Q

Select_range

A

The number of joins that used ranges on the first table. This is normally not a critical issue even if the value is quite large.

142
Q

Select_range_check

A

The number of joins without keys that check for key usage after each row. If this is not 0 you should carefully check the indexes of your tables.

143
Q

Select_scan

A

The number of joins that did a full scan of the first table.

144
Q

Slave_heartbeat_period

A

Shows the replication heartbeat interval (in seconds) on a replication slave.

145
Q

Slave_last_heartbeat

A

Shows when the most recent heartbeat signal was received by a replication slave as aTIMESTAMPvalue.

146
Q

Slave_open_temp_tables

A

The number of temporary tables that the slave SQL thread currently has open. If the value is greater than zero it is not safe to shut down the slave; seeSection16.4.1.22 “Replication and Temporary Tables”.

147
Q

Slave_received_heartbeats

A

This counter increments with each replication heartbeat received by a replication slave since the last time that the slave was restarted or reset or aCHANGE MASTER TOstatement was issued.

148
Q

Slave_retried_transactions

A

The total number of times since startup that the replication slave SQL thread has retried transactions.

149
Q

Slave_running

A

This isONif this server is a replication slave that is connected to a replication master and both the I/O and SQL threads are running; otherwise it isOFF.

150
Q

Slow_launch_threads

A

The number of threads that have taken more thanslow_launch_timeseconds to create.

151
Q

Slow_queries

A

The number of queries that have taken more thanlong_query_timeseconds. This counter increments regardless of whether the slow query log is enabled. For information about that log seeSection5.2.5 “The Slow Query Log”.

152
Q

Sort_merge_passes

A

The number of merge passes that the sort algorithm has had to do. If this value is large you should consider increasing the value of thesort_buffer_sizesystem variable.

153
Q

Sort_range

A

The number of sorts that were done using ranges.

154
Q

Sort_rows

A

The number of sorted rows.

155
Q

Sort_scan

A

The number of sorts that were done by scanning the table.

156
Q

Ssl_accept_renegotiates

A

The number of negotiates needed to establish the connection.

157
Q

Ssl_accepts

A

The number of accepted SSL connections.

158
Q

Ssl_callback_cache_hits

A

The number of callback cache hits.

159
Q

Ssl_cipher

A

The current SSL cipher (empty for non-SSL connections).

160
Q

Ssl_cipher_list

A

The list of possible SSL ciphers.

161
Q

Ssl_client_connects

A

The number of SSL connection attempts to an SSL-enabled master.

162
Q

Ssl_connect_renegotiates

A

The number of negotiates needed to establish the connection to an SSL-enabled master.

163
Q

Ssl_ctx_verify_depth

A

The SSL context verification depth (how many certificates in the chain are tested).

164
Q

Ssl_ctx_verify_mode

A

The SSL context verification mode.

165
Q

Ssl_default_timeout

A

The default SSL timeout.

166
Q

Ssl_finished_accepts

A

The number of successful SSL connections to the server.

167
Q

Ssl_finished_connects

A

The number of successful slave connections to an SSL-enabled master.

168
Q

Ssl_server_not_after

A

The last date for which the SSL certificate is valid. This variable was added in MySQL 5.6.3.

169
Q

Ssl_server_not_before

A

The first date for which the SSL certificate is valid. This variable was added in MySQL 5.6.3.

170
Q

Ssl_session_cache_hits

A

The number of SSL session cache hits.

171
Q

Ssl_session_cache_misses

A

The number of SSL session cache misses.

172
Q

Ssl_session_cache_mode

A

The SSL session cache mode.

173
Q

Ssl_session_cache_overflows

A

The number of SSL session cache overflows.

174
Q

Ssl_session_cache_size

A

The SSL session cache size.

175
Q

Ssl_session_cache_timeouts

A

The number of SSL session cache timeouts.

176
Q

Ssl_sessions_reused

A

How many SSL connections were reused from the cache.

177
Q

Ssl_used_session_cache_entries

A

How many SSL session cache entries were used.

178
Q

Ssl_verify_depth

A

The verification depth for replication SSL connections.

179
Q

Ssl_verify_mode

A

The verification mode for replication SSL connections.

180
Q

Ssl_version

A

The SSL protocol version of the connection.

181
Q

Table_locks_immediate

A

The number of times that a request for a table lock could be granted immediately.

182
Q

Table_locks_waited

A

The number of times that a request for a table lock could not be granted immediately and a wait was needed. If this is high and you have performance problems you should first optimize your queries and then either split your table or tables or use replication.

183
Q

Table_open_cache_hits

A

The number of hits for open tables cache lookups. This variable was added in MySQL 5.6.6.

184
Q

Table_open_cache_misses

A

The number of misses for open tables cache lookups. This variable was added in MySQL 5.6.6.

185
Q

Table_open_cache_overflows

A

The number of overflows for the open tables cache. This is the number of times after a table is opened or closed a cache instance has an unused entry and the size of the instance is larger thantable_open_cache/table_open_cache_instances. This variable was added in MySQL 5.6.6.

186
Q

Tc_log_max_pages_used

A

For the memory-mapped implementation of the log that is used bymysqldwhen it acts as the transaction coordinator for recovery of internal XA transactions this variable indicates the largest number of pages used for the log since the server started. If the product ofTc_log_max_pages_usedandTc_log_page_sizeis always significantly less than the log size the size is larger than necessary and can be reduced. (The size is set by the–log-tc-sizeoption. Currently this variable is unused: It is unneeded for binary log-based recovery and the memory-mapped recovery log method is not used unless the number of storage engines capable of two-phase commit is greater than one. (InnoDBis the only applicable engine.)

187
Q

Tc_log_page_size

A

The page size used for the memory-mapped implementation of the XA recovery log. The default value is determined usinggetpagesize(). Currently this variable is unused for the same reasons as described forTc_log_max_pages_used.

188
Q

Tc_log_page_waits

A

For the memory-mapped implementation of the recovery log this variable increments each time the server was not able to commit a transaction and had to wait for a free page in the log. If this value is large you might want to increase the log size (with the–log-tc-sizeoption). For binary log-based recovery this variable increments each time the binary log cannot be closed because there are two-phase commits in progress. (The close operation waits until all such transactions are finished.)

189
Q

Threads_cached

A

The number of threads in the thread cache.

190
Q

Threads_connected

A

The number of currently open connections.

191
Q

Threads_created

A

The number of threads created to handle connections. IfThreads_createdis big you may want to increase thethread_cache_sizevalue. The cache miss rate can be calculated asThreads_created/Connections.

192
Q

Threads_running

A

The number of threads that are not sleeping.

193
Q

Uptime

A

The number of seconds that the server has been up.

194
Q

Uptime_since_flush_status

A

The number of seconds since the most recentFLUSH STATUSstatement.

195
Q

Performance_schema_xxx

A

Performance Schema status variables are listed inSection21.13 “Performance Schema Status Variables”. These variables provide information about instrumentation that could not be loaded or created due to memory constraints.

MySQL (1 decks)

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